1. Field of the Invention
Although the present invention has wider utility, it particularly relates to a method and assembly for monitoring respiration and detecting apnea in a human subject.
Apnea or the transient cessation of respiration may occur unexpectedly and tragically in infants up to the age of 3 years. It is a leading killer of infants between the ages of 1 month and 1 year, as it strikes thousands of homes every year. The cause of this mysterious killer in infants has not yet been discovered.
This killer is aptly called crib death or sudden infant death syndrome because the syndrome always seems to strike during sleep and has been found to take the lives of infants in such closely supervised environments as hospitals.
One new focal point of study in this area has been directed to the infant's central nervous system. It is known that an infant's nervous system is developed in an orderly step-by-step fashion as fetal reflexes are systematically replaced by normal postnatal reflexes. It is possible that the timing of the replacement goes wrong in some infants, that is, the fetal reflexes decay before the postnatal system is fully developed or that it isn't replaced as scheduled and there are two systems working at once. Also, it is known that reflexes change during sleep, thereby altering the patterns of breathing, pulse rate and brain waves. As a result, it is possible that an underdeveloped system might simply fail to function during sleep resulting in spontaneous death.
2. Description of the Prior Art
There are many respiratory monitor systems which provide an electrical signal in response to the respiratory activity of infants. Such devices often measure by impedence pneumography or the tidal volume of the subject by a strain gauge taped directly on the abdomen of the subject. Optical breathing sensors and modulation of a high frequency carrier by a breathing sensor are also well known in monitoring respiration and detecting apnea.
Some of the problems inherent in the prior art respiration monitoring devices are: the inconvenience of bonding electrodes to the infant, the possible problem of shocking the infant with an electrical current and the problem of the human subject removing the sensor, either advertently or inadvertently.